Pore spaces are completely filled with oil to the extent that oil flows out when disturbed. (May also consist of weathered oil such as a buried lens of asphalt oil.)

Subsurface Oil DescriptionsPP, Partially filled pores

Pore spaces partially filled with oil to the extent that oil does not flow out when disturbed.

Subsurface Oil DescriptionsOR, Oil residue

Sediments are visibly oiled with black/brown coats or covered on the clasts (individual sediment particles) but little or no residue in pore spaces. Modifiers are Heavy HOR , Moderate MOR, and Light LOR.